1. Field of the Invention
This invention relates to inflation valves, and more particularly to inflation valves used in conjunction with pressurized containers of an inflation substance such as carbon dioxide gas or other gases in liquid or gaseous form to inflate life rafts, life jackets, emergency slides and the like.
2. Description of the Prior Art
U.S. Pat. No. 2,564,686 to Gray discloses a valve mechanism for use in fluid lines comprising a plunger and a first sealing gasket attached to one of its ends. A second sealing gasket attached to the other end of the plunger is mounted outside the body of the valve assembly, and closes a vent when the valve is in the open position. In the closed position, the first sealing gasket is positioned in the bore between the inlet and outlet conduits, and the second sealing gasket opens the vent to prevent fluid pressure build up in the line.
Inflation valves on pressurized containers connected to emergency equipment such as life rafts are known in the art. Oliphant (U.S. Pat. No. 3,150,388) discloses a spring biased piston valve that is actuated once pressure in the container has dropped and the emergency equipment has been partially inflated using a first valve mechanism. This enables the rapid discharge of a large volume of the pressurized bottle's contents.
In U.S. Pat. No. 4,549,870 Wass discloses an inflation valve having a double-ended piston of uniform diameter having O-ring seals on both ends of the piston which is actuated by a pull-type firing mechanism. Wass also discloses a piston rod attached to a piston head having O-ring seals thereon in U.S. Pat. No. 4,595,374. In the latter invention the valve mechanism is actuated when a detachable cable causes axial movement of the outer end of the piston rod past a safety mechanism. In both Wass patents the force necessary to operate the valve is that amount of force necessary to overcome the drag of the O-ring seals.
The prior art patents disclose valves closed by positioning the piston head over a conduit thereby blocking passage of the pressurized fluid from its container to the outlet valve.
There is a need for an inflation valve wherein the amount of force necessary to operate it can be varied, and for a valve which can be opened with a small amount of force.